Children of the Deep (Su) Once per day, while in an aquatic environment, a merfolk vampire can call forth a crab swarm, 1d4+1 sharks, or 2d6 squids as a standard action. These creatures arrive in 2d6 rounds and serve the vampire for up to 1 hour.

Create Spawn (Su) A vampire can create spawn out of those it slays with blood drain or energy drain,
provided that the slain creature is of the same creature type as the
vampire's base creature type. The victim rises from death as a vampire
in 1d4 days. This vampire is under the command of the vampire that
created it, and remains enslaved until its master's destruction. A
vampire may have enslaved spawn totaling no more than twice its own Hit Dice; any spawn it creates that would exceed this limit become free-willed undead. A vampire may free an enslaved spawn in order to enslave a new spawn, but once freed, a vampire or vampire spawn cannot be enslaved again.

Dominate (Su) A vampire can crush a humanoid opponent's will as a standard action. Anyone the vampire targets must succeed on a Will save or fall instantly under the vampire's influence, as though by a dominate person spell (caster level
12th). The ability has a range of 30 feet. At the GM's discretion, some
vampires might be able to affect different creature types with this
power.

Energy Drain (Su) A creature hit by a vampire's slam (or other natural weapon) gains two negative levels. This ability only triggers once per round, regardless of the number of attacks a vampire makes.

Gaseous Form (Su) As a standard action, a vampire can assume gaseous form at will (caster level 5th), but it can remain gaseous indefinitely and has a fly speed of 20 feet with perfect maneuverability.

Shadowless (Ex) A vampire casts no shadows and shows no reflection in a mirror.

Spider Climb (Ex) A vampire can climb sheer surfaces as though under the effects of a spider climb spell.

Vampire Weaknesses (Ex) Merfolk vampires cannot tolerate the
strong odor of garlic and will not enter an area laced with it.
Similarly, they recoil from mirrors or strongly presented holy symbols.
These things don't harm the vampire—they merely keep it at bay. A
recoiling vampire must stay at least 5 feet away from the mirror or holy
symbol and cannot touch or make melee attacks against that creature.
Holding a vampire at bay takes a standard action. After 1 round, a
vampire can overcome its revulsion of the object and function normally
each round it makes a DC 25 Will save. Merfolk vampires cannot enter a
private home or dwelling unless invited in by someone with the authority
to do so.

Noted for their distinctive, green teeth, merfolk vampires are cruel undead able to walk about on land in the form of a human or swim the oceans in the form of a shark in addition to their native, hybrid form. A typical merfolk vampire has a connection with fey beings as well as with death, possessing sorcerer levels and a fey bloodline. Though able to drink the blood and drain the energy of the living, merfolk vampires are neither compelled to do so nor driven to do so by hunger. They do, however, commit murder as a perverse form of entertainment.

A merfolk vampire's preferred method of dispatching a victim is drowning. Unless the vampire feels threatened enough to resort to spells and other powerful attacks, it attempts to lure its victims to the shore, grapple them, and drag them under the waves (or above the waves, in the case of aquatic victims). Since this tactic is ineffective against amphibious creatures such as merfolk, those beings are less likely to be targeted by merfolk vampires than creatures that breath only air or only water.